Need good helper soon after arriving

I've been looking into getting a helper before I arrive in HK, since we need one shortly after arriving in mid-July (or ideally when we arrive).

But our HKID will be available only about a week after we arrive and then we won't have utility bills, etc. for quite a while, so it seems an overseas helper is not possible given our time frame.

Is our only option to find someone with an HKID?
Can they start work right away? Do they live in? Do they receive the same salary as an overseas maid?

What do people usually do when they just come in from overseas and both spouses need to work? Our companies are handling some things (like our HKID), but we are renting our own apartment and need to find our own helper.

We need a live-in helper who can shop, cook, clean, do laundry, and interact well with our two school-age sons (English or Putongua is fine).